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1.
Am J Physiol Endocrinol Metab ; 326(5): E626-E639, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38536037

RESUMEN

Loss of ovarian function imparts increased susceptibility to obesity and metabolic disease. These effects are largely attributed to decreased estradiol (E2), but the role of increased follicle-stimulating hormone (FSH) in modulating energy balance has not been fully investigated. Previous work that blocked FSH binding to its receptor in mice suggested this hormone may play a part in modulating body weight and energy expenditure after ovariectomy (OVX). We used an alternate approach to isolate the individual and combined contributions of FSH and E2 in mediating energy imbalance and changes in tissue-level metabolic health. Female Wistar rats were ovariectomized and given the gonadotropin releasing hormone (GnRH) antagonist degarelix to suppress FSH production. E2 and FSH were then added back individually and in combination for a period of 3 wk. Energy balance, body mass composition, and transcriptomic profiles of individual tissues were obtained. In contrast to previous studies, suppression and replacement of FSH in our paradigm had no effect on body weight, body composition, food intake, or energy expenditure. We did, however, observe organ-specific effects of FSH that produced unique transcriptomic signatures of FSH in retroperitoneal white adipose tissue. These included reductions in biological processes related to lipogenesis and carbohydrate transport. In addition, rats administered FSH had reduced liver triglyceride concentration (P < 0.001), which correlated with FSH-induced changes at the transcriptomic level. Although not appearing to modulate energy balance after loss of ovarian function in rats, FSH may still impart tissue-specific effects in the liver and white adipose tissue that might affect the metabolic health of those organs.NEW & NOTEWORTHY We find no effect of follicle-stimulating hormone (FSH) on energy balance using a novel model in which rats are ovariectomized, subjected to gonadotropin-releasing hormone antagonism, and systematically given back FSH by osmotic pump. However, tissue-specific effects of FSH on adipose tissue and liver were observed in this study. These include unique transcriptomic signatures induced by the hormone and a stark reduction in hepatic triglyceride accumulation.


Asunto(s)
Metabolismo Energético , Estradiol , Hormona Folículo Estimulante , Ovariectomía , Ratas Wistar , Animales , Femenino , Metabolismo Energético/efectos de los fármacos , Ratas , Hormona Folículo Estimulante/metabolismo , Estradiol/farmacología , Composición Corporal/efectos de los fármacos , Peso Corporal/efectos de los fármacos , Ovario/efectos de los fármacos , Ovario/metabolismo , Tejido Adiposo Blanco/metabolismo , Tejido Adiposo Blanco/efectos de los fármacos , Hígado/metabolismo , Hígado/efectos de los fármacos , Transcriptoma/efectos de los fármacos
2.
Am J Physiol Heart Circ Physiol ; 326(1): H123-H137, 2024 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-37921669

RESUMEN

Vascular aging, featuring endothelial dysfunction and large elastic artery stiffening, is a major risk factor for the development of age-associated cardiovascular diseases (CVDs). Vascular aging is largely mediated by an excessive production of reactive oxygen species (ROS) and increased inflammation leading to reduced bioavailability of the vasodilatory molecule nitric oxide and remodeling of the arterial wall. Other cellular mechanisms (i.e., mitochondrial dysfunction, impaired stress response, deregulated nutrient sensing, cellular senescence), termed "hallmarks" or "pillars" of aging, may also contribute to vascular aging. Gonadal aging, which largely impacts women but also impacts some men, modulates the vascular aging process. Regular physical activity, including both aerobic and resistance exercise, is a first-line strategy for reducing CVD risk with aging. Although exercise is an effective intervention to counter vascular aging, there is considerable variation in the vascular response to exercise training with aging. Aerobic exercise improves large elastic artery stiffening in both middle-aged/older men and women and enhances endothelial function in middle-aged/older men by reducing oxidative stress and inflammation and preserving nitric oxide bioavailability; however, similar aerobic exercise training improvements are not consistently observed in estrogen-deficient postmenopausal women. Sex differences in adaptations to exercise may be related to gonadal aging and declines in estrogen in women that influence cellular-molecular mechanisms, disconnecting favorable signaling in the vasculature induced by exercise training. The present review will summarize the current state of knowledge on vascular adaptations to regular aerobic and resistance exercise with aging, the underlying mechanisms involved, and the moderating role of biological sex.


Asunto(s)
Enfermedades Cardiovasculares , Rigidez Vascular , Persona de Mediana Edad , Femenino , Humanos , Masculino , Anciano , Óxido Nítrico , Endotelio Vascular , Envejecimiento/fisiología , Ejercicio Físico/fisiología , Enfermedades Cardiovasculares/prevención & control , Inflamación , Estrógenos , Rigidez Vascular/fisiología
3.
Am J Physiol Heart Circ Physiol ; 326(1): H238-H255, 2024 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-37999647

RESUMEN

In cardiovascular research, sex and gender have not typically been considered in research design and reporting until recently. This has resulted in clinical research findings from which not only all women, but also gender-diverse individuals have been excluded. The resulting dearth of data has led to a lack of sex- and gender-specific clinical guidelines and raises serious questions about evidence-based care. Basic research has also excluded considerations of sex. Including sex and/or gender as research variables not only has the potential to improve the health of society overall now, but it also provides a foundation of knowledge on which to build future advances. The goal of this guidelines article is to provide advice on best practices to include sex and gender considerations in study design, as well as data collection, analysis, and interpretation to optimally establish rigor and reproducibility needed to inform clinical decision-making and improve outcomes. In cardiovascular physiology, incorporating sex and gender is a necessary component when optimally designing and executing research plans. The guidelines serve as the first guidance on how to include sex and gender in cardiovascular research. We provide here a beginning path toward achieving this goal and improve the ability of the research community to interpret results through a sex and gender lens to enable comparison across studies and laboratories, resulting in better health for all.


Asunto(s)
Investigación Biomédica , Cardiología , Caracteres Sexuales , Femenino , Humanos , Masculino , Sistema Cardiovascular
4.
Circ Res ; 130(4): 496-511, 2022 02 18.
Artículo en Inglés | MEDLINE | ID: mdl-35175843

RESUMEN

Peripheral artery disease (PAD) is a prevalent condition that confers substantial morbidity and mortality and remains underdiagnosed as well as undertreated in the overall population. Although PAD prevalence is similar or higher in women compared with men, associations of traditional and nontraditional risk factors with PAD and clinical manifestations of PAD differ by sex and may contribute to delayed or lack of diagnosis in women. Such sex-based differences in the manifestation of PAD may arise from sexual dimorphism in the vascular substrate in health as well as sex variation in the responses to vascular stressors. Despite the availability of proven therapies for improving symptoms and reducing risk of ischemic cardiovascular and limb events among patients with diagnosed PAD, important sex differences in treatment and outcomes have been observed. We provide an overview of current knowledge regarding sex differences in the epidemiology, pathophysiology, clinical presentation, and management of PAD.


Asunto(s)
Enfermedad Arterial Periférica/diagnóstico , Enfermedad Arterial Periférica/epidemiología , Caracteres Sexuales , Índice Tobillo Braquial/métodos , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/epidemiología , Diabetes Mellitus/fisiopatología , Diabetes Mellitus/terapia , Terapia por Ejercicio/métodos , Femenino , Fibrinolíticos/uso terapéutico , Humanos , Hipertensión/diagnóstico , Hipertensión/epidemiología , Hipertensión/fisiopatología , Hipertensión/terapia , Masculino , Enfermedad Arterial Periférica/fisiopatología , Enfermedad Arterial Periférica/terapia , Factores Sexuales , Fumar/efectos adversos , Fumar/epidemiología , Fumar/fisiopatología
5.
J Am Soc Nephrol ; 34(8): 1433-1444, 2023 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-37228030

RESUMEN

SIGNIFICANCE STATEMENT: Lower serum bicarbonate levels, even within the normal range, are strongly linked to risks of cardiovascular disease in CKD, possibly by modifying vascular function. In this randomized, controlled trial, treatment with sodium bicarbonate (NaHCO 3 ) did not improve vascular endothelial function or reduce arterial stiffness in participants with CKD stage 3b-4 with normal serum bicarbonate levels. In addition, NaHCO 3 treatment did not reduce left ventricular mass index. NaHCO 3 did increase plasma bicarbonate levels and urinary citrate excretion and reduce urinary ammonium excretion, indicating that the intervention was indeed effective. NaHCO 3 therapy was safe with no significant changes in BP, weight, or edema. These results do not support the use of NaHCO 3 for vascular dysfunction in participants with CKD. BACKGROUND: Lower serum bicarbonate levels, even within the normal range, are strongly linked to risks of cardiovascular disease in CKD, possibly by modifying vascular function. Prospective interventional trials with sodium bicarbonate (NaHCO 3 ) are lacking. METHODS: We conducted a randomized, double-blind, placebo-controlled trial examining the effect of NaHCO 3 on vascular function in 109 patients with CKD stage 3b-4 (eGFR 15-44 ml/min per 1.73 m 2 ) with normal serum bicarbonate levels (22-27 mEq/L). Participants were randomized 1:1 to NaHCO 3 or placebo at a dose of 0.5 mEq/lean body weight-kg per day for 12 months. The coprimary end points were change in brachial artery flow-mediated dilation (FMD) and change in aortic pulse wave velocity over 12 months. RESULTS: Ninety patients completed this study. After 12 months, plasma bicarbonate levels increased significantly in the NaHCO 3 group compared with placebo (mean [SD] difference between groups 1.35±2.1, P = 0.003). NaHCO 3 treatment did not result in a significant improvement in aortic pulse wave velocity from baseline. NaHCO 3 did result in a significant increase in flow-mediated dilation after 1 month; however, this effect disappeared at 6 and 12 months. NaHCO 3 resulted in a significant increase in 24-hour urine citrate and pH and a significant decrease in 24-hour urine ammonia. There was no significant change in left ventricular mass index, ejection fraction, or eGFR with NaHCO 3 . NaHCO 3 treatment was safe and well-tolerated with no significant changes in BP, antihypertensive medication, weight, plasma calcium, or potassium levels. CONCLUSION: Our results do not support the use of NaHCO 3 for vascular dysfunction in participants with CKD and normal serum bicarbonate levels.


Asunto(s)
Enfermedades Cardiovasculares , Insuficiencia Renal Crónica , Humanos , Bicarbonato de Sodio/uso terapéutico , Bicarbonatos , Enfermedades Cardiovasculares/etiología , Enfermedades Cardiovasculares/prevención & control , Análisis de la Onda del Pulso , Estudios Prospectivos , Insuficiencia Renal Crónica/complicaciones , Insuficiencia Renal Crónica/tratamiento farmacológico , Método Doble Ciego
6.
J Physiol ; 601(8): 1371-1382, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36891609

RESUMEN

Mounting evidence suggests that myocardial steatosis contributes to left ventricular diastolic dysfunction, but definitive evidence in humans is lacking due to confounding comorbidities. As such, we utilized a 48-h food restriction model to acutely increase myocardial triglyceride (mTG) content - measured by 1 H magnetic resonance spectroscopy - in 27 young healthy volunteers (13 men/14 women). Forty-eight hours of fasting caused a more than 3-fold increase in mTG content (P < 0.001). Diastolic function - defined as early diastolic circumferential strain rate (CSRd) - was unchanged following the 48-h fasting intervention, but systolic circumferential strain rate was elevated (P < 0.001), indicative of systolic-diastolic uncoupling. Indeed, in a separate control experiment in 10 individuals, administration of low-dose dobutamine (2 µg/kg/min) caused a similar change in systolic circumferential strain rate as was found during 48 h of food restriction, along with a proportionate increase in CSRd, such that the two metrics remained coupled. Taken together, these data indicate that myocardial steatosis contributes to diastolic dysfunction by impairing diastolic-systolic coupling in healthy adults, and suggest that steatosis may contribute to the progression of heart disease. KEY POINTS: Preclinical evidence strongly suggests that myocardial lipid accumulation (termed steatosis) is an important mechanism driving heart disease. Definitive evidence in humans is limited due to the confounding influence of multiple underlying comorbidities. Using a 48-h food restriction model to acutely increase myocardial triglyceride content in young healthy volunteers, we demonstrate an association between myocardial steatosis and left ventricular diastolic dysfunction. These data advance the hypothesis that myocardial steatosis may contribute to diastolic dysfunction and suggest myocardial steatosis as a putative therapeutic target.


Asunto(s)
Cardiomiopatías , Disfunción Ventricular Izquierda , Masculino , Adulto , Humanos , Femenino , Función Ventricular Izquierda , Diástole , Miocardio , Triglicéridos
7.
Am J Physiol Heart Circ Physiol ; 325(5): H1118-H1125, 2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-37682233

RESUMEN

Mechanisms underlying sex differences in brain aging remain unclear but may relate to changes in cerebral pulsatile blood flow. Sex differences in the stiffening of the large arteries and expansion of pulse pressure with age may accelerate changes in pulsatile (i.e., discontinuous) blood flow in the brain that contribute to brain health. The purpose of this cross-sectional, secondary analysis was to examine sex differences in age-associated changes in large artery (aorta and carotid) stiffness, carotid pulse pressure, and cerebral pulsatility in 206 men and 217 women between 18 and 72 yr of age. Outcomes included aortic stiffness [carotid-femoral pulse wave velocity (cfPWV)] and carotid pulse pressure via tonometry, carotid ß-stiffness via ultrasound, and middle cerebral artery (MCA) pulsatility index via transcranial Doppler. Regression analyses revealed a significant age-by-sex interaction, with women exhibiting a slower rate of change compared with men for cfPWV (ß = -0.21, P = 0.04), and greater rate of change for carotid stiffness (ß = 0.27, P = 0.02), carotid pulse pressure (ß = 0.98, P < 0.001), and MCA pulsatility index (ß = 0.49, P = 0.002) after adjustment for covariates. The significant age-by-sex interaction for MCA pulsatility was abolished after further adjustment for carotid pulse pressure. Women exhibit accelerated increases in cerebral pulsatility during midlife, likely driven by exaggerated increases in carotid stiffness and pulse pressure compared with men. These data suggest that there are disproportionate increases in cerebral pulsatility in women during midlife that could contribute to accelerated brain aging compared with men.NEW & NOTEWORTHY We identify sex-specific associations between increasing age and cerebral pulsatility and its vascular mechanisms. When compared with men, women in our cross-sectional analysis exhibited greater age-associated increases in carotid stiffness, carotid pulse pressure, and cerebral pulsatility particularly during midlife. These data suggest that the rapid expansion of pulse pressure during midlife contributes to an exaggerated increase in cerebral pulsatility among women and suggest a potential mechanism contributing to sex differences in brain aging.


Asunto(s)
Arteria Cerebral Media , Análisis de la Onda del Pulso , Humanos , Femenino , Masculino , Estudios Transversales , Arteria Cerebral Media/diagnóstico por imagen , Presión Sanguínea , Encéfalo/diagnóstico por imagen
8.
Am J Physiol Heart Circ Physiol ; 324(6): H893-H904, 2023 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-37115626

RESUMEN

The aorta stiffens with aging in both men and women, which predicts cardiovascular mortality. Aortic wall structural and extracellular matrix (ECM) remodeling, induced in part by chronic low-grade inflammation, contribute to aortic stiffening. Male mice are an established model of aortic aging. However, there is little information regarding whether female mice are an appropriate model of aortic aging in women, which we aimed to elucidate in the present study. We assessed two strains of mice and found that in C57BL/6N mice, in vivo aortic stiffness (pulse wave velocity, PWV) was higher with aging in both sexes, whereas in B6D2F1 mice, PWV was higher in old versus young male mice, but not in old versus young female mice. Because the age-related stiffening that occurs in men and women was reflected in male and female C57BL/6N mice, we examined the mechanisms of stiffening in this strain. In both sexes, aortic modulus of elasticity (pin myography) was lower in old mice, occurred in conjunction with and was related to higher plasma levels of the elastin-degrading enzyme matrix metalloproteinase-9 (MMP-9), and was accompanied by higher numbers of aortic elastin breaks and higher abundance of adventitial collagen-1. Plasma levels of the inflammatory cytokines interferon-γ, interleukin 6, and monocyte chemoattractant protein-1 were higher in both sexes of old mice. In conclusion, female C57BL/6N mice exhibit aortic stiffening, reduced modulus of elasticity and structural/ECM remodeling, and associated increases in MMP-9 and systemic inflammation with aging, and thus are an appropriate model of aortic aging in women.NEW & NOTEWORTHY Our study demonstrates that with aging, female C57BL/6N mice exhibit higher in vivo aortic stiffness, reduced modulus of elasticity, aortic wall structural and extracellular matrix remodeling, and elevations in systemic inflammation. These changes are largely reflective of those that occur with aging in women. Thus, female C57BL/6N mice are a viable model of human aortic aging and the utility of these animals should be considered in future biomedical investigations.


Asunto(s)
Elastina , Rigidez Vascular , Humanos , Animales , Ratones , Femenino , Masculino , Metaloproteinasa 9 de la Matriz , Análisis de la Onda del Pulso , Ratones Endogámicos C57BL , Aorta , Envejecimiento , Inflamación
9.
Circulation ; 144(6): e136-e148, 2021 08 10.
Artículo en Inglés | MEDLINE | ID: mdl-34235936

RESUMEN

There is growing evidence that people who are transgender and gender diverse (TGD) are impacted by disparities across a variety of cardiovascular risk factors compared with their peers who are cisgender. Prior literature has characterized disparities in cardiovascular morbidity and mortality as a result of a higher prevalence of health risk behaviors. Mounting research has revealed that cardiovascular risk factors at the individual level likely do not fully account for increased risk in cardiovascular health disparities among people who are TGD. Excess cardiovascular morbidity and mortality is hypothesized to be driven in part by psychosocial stressors across the lifespan at multiple levels, including structural violence (eg, discrimination, affordable housing, access to health care). This American Heart Association scientific statement reviews the existing literature on the cardiovascular health of people who are TGD. When applicable, the effects of gender-affirming hormone use on individual cardiovascular risk factors are also reviewed. Informed by a conceptual model building on minority stress theory, this statement identifies research gaps and provides suggestions for improving cardiovascular research and clinical care for people who are TGD, including the role of resilience-promoting factors. Advancing the cardiovascular health of people who are TGD requires a multifaceted approach that integrates best practices into research, health promotion, and cardiovascular care for this understudied population.


Asunto(s)
Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/etiología , Fenómenos Fisiológicos Cardiovasculares , Personas Transgénero , Transexualidad , Susceptibilidad a Enfermedades , Femenino , Factores de Riesgo de Enfermedad Cardiaca , Humanos , Masculino , Pronóstico , Medición de Riesgo , Factores de Riesgo , Factores Sexuales , Estrés Fisiológico , Estrés Psicológico
10.
Am J Physiol Heart Circ Physiol ; 323(5): H975-H982, 2022 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-36149770

RESUMEN

Endothelial function (brachial artery flow-mediated dilation [FMD]) is reduced in estrogen-deficient postmenopausal women, mediated, in part, by reduced nitric oxide (NO) bioavailability, secondary to tetrahydrobiopterin (BH4) deficiency and oxidative stress. FMD is increased, but not fully restored, in postmenopausal women after acute intravenous vitamin C (VITC; superoxide scavenger) or oral BH4 supplementation. In vitro studies demonstrate that coadministration of VITC with BH4 prevents endothelial nitric oxide synthase (eNOS) uncoupling and reductions in NO by peroxynitrite. To investigate mechanisms of endothelial dysfunction in women, we assessed the separate and combined effects of VITC and BH4 to determine whether coadministration of VITC + BH4 improves FMD in healthy postmenopausal women (n = 19, 58 ± 5 yr) to premenopausal (n = 14, 36 ± 9 yr) levels, with exploratory testing in perimenopausal women (n = 8, 51 ± 3 yr). FMD was measured during acute intravenous infusions of saline (control) and VITC (∼2-3 g) ∼3 h after a single dose of oral BH4 (KUVAN, 10 mg/kg body wt) or placebo (randomized crossover, separated by ∼1 mo). Under the placebo condition, FMD was reduced in postmenopausal compared with premenopausal women during the saline infusion (5.6 ± 0.7 vs. 11.6 ± 0.9%, P < 0.001) and increased in postmenopausal women during VITC (+3.5 [1.4, 5.6]%, P = 0.001) and acute BH4 (+1.8 [0.37, 3.2]%, P = 0.01) alone. Coadministration of VITC + BH4 increased FMD in postmenopausal women (+3.0 [1.7, 4.3]%, P < 0.001), but FMD remained reduced compared with premenopausal women (P = 0.02). Exploratory analyses revealed that VITC + BH4 did not restore FMD in perimenopausal women to premenopausal levels (P = 0.045). Coadministration of VITC + BH4 does not restore FMD in menopausal women, suggesting that additional mechanisms may be involved.NEW & NOTEWORTHY Endothelial function is reduced across the menopausal stages related to increased oxidative stress associated with estrogen deficiency. In vitro studies demonstrate that coadministration of VITC with BH4 prevents endothelial nitric oxide synthase (eNOS) uncoupling and reductions in NO by peroxynitrite; however, this remains untested in humans. We demonstrate that the coadministration of BH4 + VITC does not restore endothelial function in perimenopausal and postmenopausal women to the level of premenopausal women, suggesting that other mechanisms contribute.


Asunto(s)
Óxido Nítrico Sintasa de Tipo III , Enfermedades Vasculares , Humanos , Femenino , Óxido Nítrico Sintasa de Tipo III/metabolismo , Endotelio Vascular/metabolismo , Ácido Peroxinitroso/metabolismo , Biopterinas/metabolismo , Biopterinas/farmacología , Menopausia , Estrógenos/metabolismo , Óxido Nítrico/metabolismo , Estrés Oxidativo
11.
Am J Physiol Renal Physiol ; 319(1): F33-F40, 2020 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-32421350

RESUMEN

Vascular dysfunction plays an important role in the etiology of chronic kidney disease (CKD) and is associated with cardiovascular diseases. Sex differences in vascular function are common in clinical and nonclinical populations. However, no data exist in individuals with CKD. The present study tested the hypothesis that sex and/or aging differences exist in vascular function in patients with CKD. Endothelium-dependent dilation (EDD; measured via brachial artery flow-mediated dilation) and endothelium-independent dilation (EID; measured via nitroglycerin-mediated dilation) were assessed. Analyses were adjusted for several variables that could influence vascular function (diabetes, cardiovascular disease, and blood pressure). Women, in general, had higher EDD values than men (6.5 ± 4.9% vs. 4.4 ± 3.4%); however, EID did not differ among these groups. In younger men and women (<55 yr old), EDD and EID were higher (P < 0.05) than their older (≥55 yr old) counterparts (EDD: 7.0 ± 4.1% vs. 4.4 ± 3.8% and EID: 24.0 ± 9.6% vs. 18.3 ± 9.2%). Additionally, younger women exhibited higher (P < 0.05) EDD and EID compared with younger men (EDD: 9.5 ± 6.4% vs. 5.1 ± 3.8%, P = 0.01, and EID: 24.0 ± 9.6% vs. 18.3 ± 9.2%). No differences in EDD and EID were present between older men and women with CKD. Diabetes independently predicted lower EID but not EDD in men and women. Blood pressure and cardiovascular disease did not predict EDD or EID. This is the first study to show significant sex differences in vascular function. Moreover, these differences are evident between younger men and women with CKD but are abolished with age. Additional studies are needed to better understand the mechanisms that may underlie sex differences in vascular dysfunction with CKD.


Asunto(s)
Arteria Braquial/fisiopatología , Endotelio Vascular/fisiopatología , Flujo Sanguíneo Regional/fisiología , Insuficiencia Renal Crónica/fisiopatología , Vasodilatación/fisiología , Adulto , Factores de Edad , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores Sexuales
12.
J Physiol ; 597(19): 4901-4914, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31077372

RESUMEN

Cardiovascular diseases (CVD) remain the leading cause of morbidity and mortality in both men and women in developed societies. Age is the greatest risk factor for CVD due largely to adverse changes to arteries that include stiffening of the large elastic arteries (aortic and carotid arteries) and endothelial dysfunction. Vascular ageing is driven by oxidative stress, which reduces nitric oxide (NO) bioavailability and stimulates changes in the extracellular matrix. In women, reductions in circulating oestrogens with menopause interact with ageing processes to induce vascular dysfunction. Regular aerobic exercise is the most evidence-based strategy for reducing CVD risk with ageing in both men and women. Much of this cardiovascular-protective effect of aerobic exercise is likely due to its vascular health-enhancing influence. Large elastic artery stiffening with advancing age is attenuated in healthy adults engaged in aerobic exercise training, and aerobic exercise interventions improve arterial stiffness in previously sedentary middle-aged and older men and postmenopausal women. Regular aerobic exercise also enhances endothelial function with ageing in men (by reducing oxidative stress and preserving NO bioavailability), but not consistently in oestrogen-deficient postmenopausal women. In postmenopausal women, treatment with oestradiol appears to restore the ability of aerobic exercise to improve NO-mediated endothelial function by reducing oxidative stress. Several research gaps exist in our understanding of potential sex differences in the vascular adaptations to regular aerobic exercise. More information is needed on the factors that are responsible for sex differences, including the role of circulating oestrogens in transducing the aerobic exercise training 'stimulus'.


Asunto(s)
Envejecimiento/fisiología , Fenómenos Fisiológicos Cardiovasculares , Ejercicio Físico/fisiología , Femenino , Humanos , Masculino , Estrés Oxidativo
13.
Am J Physiol Heart Circ Physiol ; 316(3): H522-H526, 2019 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-30632767

RESUMEN

This review summarizes a presentation given during the "Countermeasures to Cardiovascular Aging Symposium" that was part of the American Physiological Society Conference on Cardiovascular Aging: New Frontiers and Old Friends held in Westminster, CO, in August 2017. Endothelial dysfunction, a characteristic of vascular aging, is a major risk factor for age-associated cardiovascular diseases. In women, the decline in endothelial function is attenuated until menopause, whereafter the rate of decline accelerates to match that seen in men. Sex differences in the decline in endothelial function have been attributed to changes in sex hormones with aging. Women have a progressive impairment in endothelial function across the stages of the menopause transition, related in part to declining estradiol levels. In contrast to women, little is known about the impact of declining testosterone levels on endothelial function in men. Some evidence suggests greater endothelial dysfunction in men with low testosterone compared with men with higher testosterone. The underlying causes of endothelial dysfunction with sex hormone deficiency are unknown but may be related to endothelial nitric oxide synthase dysfunction and oxidative stress. Lifestyle behaviors, including habitual endurance exercise, attenuates and reverses the age-associated decline in endothelial function in older men. However, in older women, these exercise adaptations are diminished or absent, possibly related to estrogen deficiency. Understanding how declines in sex hormones contribute to the vascular aging process in both women and men will inform effective sex-specific intervention strategies to preserve vascular health and prevent cardiovascular diseases.


Asunto(s)
Envejecimiento/fisiología , Vasos Sanguíneos/crecimiento & desarrollo , Vasos Sanguíneos/fisiología , Hormonas Esteroides Gonadales/fisiología , Anciano , Animales , Femenino , Humanos , Masculino , Caracteres Sexuales , Enfermedades Vasculares
15.
J Inherit Metab Dis ; 42(3): 424-437, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30873612

RESUMEN

STUDY OBJECTIVE: A phase 1/2 clinical trial was performed in individuals with cystathionine ß synthase (CBS) deficient homocystinuria with aims to: (a) assess pharmacokinetics and safety of taurine therapy, (b) evaluate oxidative stress, inflammation, and vascular function in CBS deficiency, and (c) evaluate the impact of short-term taurine treatment. METHODS: Individuals with pyridoxine-nonresponsive CBS deficiency with homocysteine >50 µM, without inflammatory disorder or on antioxidant therapy were enrolled. Biomarkers of oxidative stress and inflammation, endothelial function (brachial artery flow-mediated dilation [FMD]), and disease-related metabolites obtained at baseline were compared to normal values. While maintaining current treatment, patients were treated with 75 mg/kg taurine twice daily, and treatment response assessed after 4 hours and 4 days. RESULTS: Fourteen patients (8-35 years; 8 males, 6 females) were enrolled with baseline homocysteine levels 161 ± 67 µM. The study found high-dose taurine to be safe when excluding preexisting hypertriglyceridemia. Taurine pharmacokinetics showed a rapid peak level returning to near normal levels at 12 hours, but had slow accumulation and elevated predosing levels after 4 days of treatment. Only a single parameter of oxidative stress, 2,3-dinor-8-isoprostaglandin-F2α, was elevated at baseline, with no elevated inflammatory parameters, and no change in FMD values overall. Taurine had no effect on any of these parameters. However, the effect of taurine was strongly related to pretreatment FMD values; and taurine significantly improved FMD in the subset of individuals with pretreatment FMD values <10% and in individuals with homocysteine levels >125 µM, pertinent to endothelial function. CONCLUSION: Taurine improves endothelial function in CBS-deficient homocystinuria in patients with preexisting reduced function.


Asunto(s)
Biomarcadores/metabolismo , Cistationina betasintasa/metabolismo , Homocistinuria/tratamiento farmacológico , Taurina/farmacocinética , Taurina/uso terapéutico , Adolescente , Adulto , Arteria Braquial/efectos de los fármacos , Niño , Cistationina betasintasa/deficiencia , Femenino , Homocisteína/metabolismo , Homocistinuria/genética , Humanos , Inflamación/tratamiento farmacológico , Masculino , Estrés Oxidativo/efectos de los fármacos , Estados Unidos , Adulto Joven
16.
Int J Behav Med ; 26(6): 600-607, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31732904

RESUMEN

BACKGROUND: Attention difficulties are often reported by patients with chronic obstructive pulmonary disease (COPD); however, limited research exists using objective tests designed specifically to measure attention in this population. This study aimed to (1) identify specific attention deficits in COPD and (2) determine which demographic/clinical characteristics are associated with reduced attention. METHODS: Eighty-four former smokers (53 COPD, 31 no COPD) completed questionnaires, pulmonary function testing, and the Conner's Continuous Performance Test II (CPT-II). Participants with and without COPD were compared on CPT-II measures of inattention, impulsivity, and vigilance. CPT-II measures that differed significantly between the two groups were further examined using hierarchical regression modeling. Demographic/clinical characteristics were entered into models with attention as the dependent variable. RESULTS: Participants with COPD performed worse than those without COPD on CPT measures of inattention and impulsivity (i.e., detectability [discrimination of target from non-target stimuli], perseverations [reaction time under 100 ms], omissions [target stimuli response failures], and commissions [responses to non-target stimuli]). More severe COPD (measured by greater airflow limitation) was associated with poorer ability to detect targets vs. foils and perseverative responding after adjusting for age and other covariates in the model. CONCLUSION: Former smokers with COPD experience problems with attention that go beyond slowed processing speed, including aspects of inattention and impulsivity. Clinicians should be aware that greater airflow limitation and older age are associated with attention difficulties, as this may impact functioning.


Asunto(s)
Atención , Enfermedad Pulmonar Obstructiva Crónica/psicología , Fumadores/psicología , Fumar/psicología , Factores de Edad , Anciano , Femenino , Humanos , Pulmón/fisiopatología , Masculino , Persona de Mediana Edad , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Pruebas de Función Respiratoria , Índice de Severidad de la Enfermedad , Fumar/fisiopatología
17.
FASEB J ; 31(7): 2771-2784, 2017 07.
Artículo en Inglés | MEDLINE | ID: mdl-28302652

RESUMEN

Ectonucleoside triphosphate diphosphohydrolase 1 (NTPDase1) degrades the purines ATP and ADP that are key regulators of inflammation and clotting. We hypothesized that NTPDase1 polymorphisms exist and that they regulate this pathway. We sequenced the ENTPD1 gene (encoding NTPDase1) in 216 subjects then assessed genotypes in 2 cohorts comprising 2213 humans to identify ENTPD1 polymorphisms associated with venous thromboembolism (VTE). The G allele of the intron 1 polymorphism rs3176891 was more common in VTE vs. controls (odds ratio 1.26-1.9); it did not affect RNA splicing, but it was in strong linkage disequilibrium with the G allele of the promoter polymorphism rs3814159, which increased transcriptional activity by 8-fold. Oligonucleotides containing the G allele of this promoter region bound nuclear extracts more avidly. Carriers of rs3176891 G had endothelial cells with increased NTPDase1 activity and protein expression, and had platelets with enhanced aggregation. Thus, the G allele of rs3176891 marks a haplotype associated with increased clotting and platelet aggregation attributable to a promoter variant associated with increased transcription, expression, and activity of NTPDase1. We term this gain-of-function phenotype observed with rs3814159 G "CD39 Denver."-Maloney, J. P., Branchford, B. R., Brodsky, G. L., Cosmic, M. S., Calabrese, D. W., Aquilante, C. L., Maloney, K. W., Gonzalez, J. R., Zhang, W., Moreau, K. L., Wiggins, K. L., Smith, N. L., Broeckel, U., Di Paola, J. The ENTPD1 promoter polymorphism -860 A > G (rs3814159) is associated with increased gene transcription, protein expression, CD39/NTPDase1 enzymatic activity, and thromboembolism risk.


Asunto(s)
Antígenos CD/metabolismo , Apirasa/metabolismo , Regulación Enzimológica de la Expresión Génica/fisiología , Polimorfismo de Nucleótido Simple , Tromboembolia Venosa/enzimología , Adulto , Empalme Alternativo , Antígenos CD/genética , Apirasa/genética , Femenino , Predisposición Genética a la Enfermedad , Genotipo , Células HEK293 , Humanos , Masculino , Persona de Mediana Edad , Tromboembolia Venosa/genética , Tromboembolia Venosa/metabolismo
18.
Exerc Sport Sci Rev ; 45(2): 116-123, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-28092297

RESUMEN

Regular exercise is promoted as a therapeutic strategy for age-associated endothelial dysfunction. Improvements in endothelial function are observed with endurance exercise in older men, but are diminished or absent in older women. This article examines the hypothesis that sex hormones modulate vascular adaptations to exercise training by influencing antioxidant defense systems, mitochondrial function, oxidative stress, and intracellular signaling.


Asunto(s)
Envejecimiento/fisiología , Endotelio Vascular/fisiología , Ejercicio Físico/fisiología , Hormonas Esteroides Gonadales/fisiología , Adaptación Fisiológica , Enfermedades Cardiovasculares/fisiopatología , Estrógenos/fisiología , Femenino , Humanos , Masculino , Factores Sexuales
19.
Vasc Med ; 22(2): 85-95, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-28095749

RESUMEN

Women with polycystic ovarian syndrome (PCOS) have evidence of subclinical cardiovascular disease (CVD). However, insulin resistance, an important factor in the development of CVD in adults, is common in adolescents with PCOS, yet data in adolescents are limited. Therefore, we sought to measure insulin resistance and CVD markers in obese youth with and without PCOS. Thirty-six PCOS and 17 non-PCOS adolescent girls who were obese, sedentary, and non-hypertensive were recruited from clinics located within the Children's Hospital Colorado. Following 3 days of controlled diet and restricted exercise, fasting plasma samples were obtained prior to a hyperinsulinemic euglycemic clamp. PCOS girls were more insulin resistant than controls (glucose infusion rate 5.24±1.86 mg/kg/min vs 9.10±2.69; p<0.001). Girls with PCOS had blood pressure in the normal range, but had greater carotid intima-media thickness (cIMT) (0.49±0.07 mm vs 0.44±0.06; p=0.038), beta stiffness index (5.1±1.3 U vs 4.4±0.9; p=0.037), and reduced arterial compliance (1.95±0.47 mm2/mmHg × 10-1 vs 2.13±0.43; p=0.047). PCOS girls had a normal mean lipid profile, yet had a more atherogenic lipoprotein cholesterol distribution and had persistent elevations of free fatty acids despite hyperinsulinemia (68±28 µmol/mL vs 41±10; p=0.001), both potential contributors to CVD. Free fatty acid concentrations correlated best with all CVD markers. In summary, adolescent girls with PCOS have greater cIMT and stiffer arteries than girls without PCOS, perhaps related to altered lipid metabolism, even when clinical measures of blood pressure and cholesterol profiles are 'normal'. Therefore, management of adolescent PCOS should include assessment of CVD risk factor development.


Asunto(s)
Enfermedades Cardiovasculares/etiología , Resistencia a la Insulina , Obesidad Infantil/complicaciones , Síndrome del Ovario Poliquístico/complicaciones , Adolescente , Biomarcadores/sangre , Glucemia/metabolismo , Presión Sanguínea , Enfermedades Cardiovasculares/sangre , Enfermedades Cardiovasculares/diagnóstico por imagen , Enfermedades Cardiovasculares/fisiopatología , Grosor Intima-Media Carotídeo , Estudios de Casos y Controles , Niño , Colorado , Femenino , Técnica de Clampeo de la Glucosa , Hospitales Pediátricos , Humanos , Mediadores de Inflamación/sangre , Insulina/sangre , Lípidos/sangre , Obesidad Infantil/sangre , Obesidad Infantil/diagnóstico , Obesidad Infantil/fisiopatología , Síndrome del Ovario Poliquístico/sangre , Síndrome del Ovario Poliquístico/diagnóstico , Síndrome del Ovario Poliquístico/fisiopatología , Medición de Riesgo , Factores de Riesgo , Rigidez Vascular , Adulto Joven
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